Fig. 1

Responses of leaf photosynthetic characteristics in two E. sibiricus genotypes to drought stress. (A) Net photosynthetic rate (Pn); (B) transpiration rate (Tr); (C) stomatal conductance (Gs); (D) intercellular carbon dioxide concentration (Ci); (E) water use efficiency (WUE); (F) limiting value of stomata (Ls). The data are presented as the means of three replicates (± SD) based on Tukey's post hoc test. Means denoted with the different letters indicate significant differences at P < 0.05. The horizontal coordinates indicate different levels of field water content (FWC). DT drought-tolerant genotype, DS drought-sensitive genotype.